The popular prior art manner of collating signatures in a saddle type of collector is to remove folded signatures from a stack and convey them to the saddle collector or raceway which receives the signatures while moving in the direction of the fold of the signatures. In that manner, the collector must move the distance of the complete length of the signature, measured along its line of fold, for each signature collected, and of course there must also be spaces between signatures on the collector. Therefore, the collector speed must be high for each signature collected thereon, since the entire length of the signature occupies a length of the collector in the direction of the eollector's movement, as mentioned. Examples of that type of prior art are seen in U.S. Pat. Nos. 2,903,260 and 3,089,693 and 3,416,786.
The present invention differs from the prior art and improves thereon by avoiding the necessity of requiring that the collector move the complete length of each folded signature in the collating process. Further, the present invention improves upon the prior art in that it moves the folded signature in a single path of movement directly from the stack of signatures and to the collector to ultimately place the signatures in a saddle type of accumulation on the collector. That is, no reversal or circuitous path of signature movement is required in the collating. Accordingly, the present invention is a high-speed type of collating method and apparatus, compared to the speed in the prior art, and thus greater production or more signatures are collated in either a given amount of time or in a given relative speed of the collector, compared to the prior art collector speed.
Still further, the present invention improves on the prior art by providing a system of vacuum take-off rollers which operate on the end of the stack of signatures to singly remove the signatures from the stack and to place them into the confines of a gripper. In this regard, the signatures are removed at relatively short intervals along the dimension of the signature so that the removed signatures form an imbricated or overlapped stream of signatures which are transported to the collector in stream relationship, rather than singly. The prior art U.S. Pat. Nos. 2,279,270 and 3,416,786 show the use of vacuum rollers for removing signatures or handling same, but they do not relate to removing signatures from a stack and into an imbricated stream relationship, as in the present invention. Accordingly, the present invention provides for the high-speed action desired and it also assures the accuracy of the procedure as well as the security of handling the signatures to avoid damage or misalignment. In the imbricated arrangement mentioned, the prior art collector is required to move a considerably greater distance than that required by the present invention, such as, the prior art collector commonly moves 25 inches per signature while the collector of this invention moves only 11/2 inches per signature collected.
Also, in accomplishing these aforesaid objectives, the present invention does not require any cam mechanisms or the like and there are only a few required moving parts for the apparatus, and those parts are readily synchronized, as required.